Have you seen him doing such pot size bluff-bets on river? Or how you are putting him on bluff-line. More often I'd play it as you did and likely fold it on river as well. More often you will see a value-bet on river there than a big bluff.

And about betting the turn it could be possible, but I am more often inclined to just Check it behind, since there aren't that many draws from we get value from anyways. And the only idea of betting the turn would be to get free showdown.